Cable splice closures in which two parts of the casing are clamped together by means of a clamping member in the form of a split ring are known. For example, U.S. Pat. No. 5,059,748 discloses a re-enterable butt cable splice closure comprising a base and a domed cover. The base and the cover each have a circumferential flange, and when the casing is closed the two flanges are brought together and a clamping member in the form of a hinged split ring is placed around the flanges and thereby clamps the base and the cover together. The clamping member comprises two semi-circular parts which are hinged together so that the member can be opened out to be placed around the flanges, and a screw threaded fastening device which fastens the hinged semi-circular parts together once the clamping member has been installed around the flanges.
International Patent Application No. WO 94/14095 (Raynet Corporation) discloses a pressure clamp for a telecommunications closure, which clamps mating parts of the closure together so as to form a watertight seal. The pressure clamp is in the form of a hinged split ring which may be hinged opened and placed around the mating surfaces of the closure parts. The clamp includes an over-centre latch which is rotatable between a first unlatched position and a second latched position, a clamping pressure generated by the latch increasing to a maximum value as the rotatable latch is moved from its first position to an intermediate position and then decreasing from this maximum value as the latch is moved from the intermediate position to the second position. A predetermined appropriate clamping pressure is generated when the latch is in its second (latched) position, so as to compress an O-ring disposed between the mating parts of the closure by an appropriate amount.
Although such clamping members work very well, they are often an expensive part of the casing due to the fact that they are formed from three or more separate parts which have to be assembled together (the three parts being, for example, the two hinged semi-circular major parts of the clamp, and the fastening device or over-centre latch). While closing a casing by means of a conventional split ring clamping member is a simple system, the clamping member itself is comparatively elaborate. Also, it can often be difficult to close the clamping member around the flanges, since, of necessity, the clamping member is a tight fit, and consequently the installation engineer often needs to use a tool to provide leverage to force the hinged parts sufficiently close together before the fastening device or over-centre latch can be used to fasten them together. Furthermore, opening the clamping member after it has been installed, in order to gain entry to the interior of the casing, can also often be difficult, requiring the use of tools to lever the hinged parts of the clamping member apart.